"He will be massive for us and I'm assuming he'll also be important for England, because the way he played the other day was very encouraging," said Zola. "There's a lot of competition in front of him because up front England are very good but he looked very good when he came on.
"He was really aggressive and I'm sure Capello, who is someone who knows his job very well, is certainly considering him as a serious option. Carlton Cole knows that this season will be the most important season of his career.
"I'm sure he can have a better season than last year. I can tell you I am not anxious to say that, for me, nobody has seen the best of Carlton Cole."
But then Zola, a former Chelsea team-mate who had long recognised Cole's qualities, took over from Alan Curbishley at West Ham last season and sparked an almost immediate turnaround.
John Terry credits Zola's influence in his development from wayward teenager to England captain - and the Italian has had a similar impact on Cole.
Zola knew what buttons to push and worked on strengthening Cole's confidence while sharpening his finishing with a series of one-on-one sessions.
"What we have done with him is to try and encourage those qualities and give him confidence and add something to his game," said Zola. "We worked with him, especially with his finishing. His movements were okay, but we just needed to improve his positivity in front of the goalkeeper, and he's been very good.
"Myself and Steve Clarke kept reminding him of the qualities he has got. He just needed to focus a little bit more on scoring and making his game a little bit more effective for the team.
"The more he has done that, the more he realised how good he was and found himself being very effective for the team.
"When John Terry started his determination and desire to improve was unbelievable. Maybe he didn't have the qualities that Carlton Cole had straight away, but there was a hunger to achieve and nobody could stop him.
"He has established positive habits and now he is growing up."